U.S. Pat. No. 6,295,734 discloses a razor blade unit which has a guard, a cap and three parallel blades mounted between the guard and the cap. At least one of blades, guard and cap can be moved from a non-shaving rest position to modify a blade exposure dimension in order to attain a target blade geometry at which shaving is initiated. As regards the target blade geometry, the exposure of the first blade is not greater than zero and the exposure of the third blade is not less than zero. At least one of the cap and the guard can be movable against the force of a spring from a rest position in which all the blades between the guard and the cap have their cutting edges disposed below a plane tangential to the skin contacting surfaces of the guard and cap. The blades can be independently sprung or carried for movement in unison on a carrier pivotally mounted in a frame of the blade unit.
One drawback of the razor blade unit is that in the initial phase of the shaving process, the risk of undesired cutting of the skin is too high. The razor blade unit is normally mounted on a longitudinal handle. A user may hold the handle in his hand and put the razor blade unit to his skin. When contacting the skin, the blades of the razor blade unit move towards the skin, which too many times leads to cutting of the skin. This may result in fast-bleeding wounds. Additionally, in practice, it has been established that it is rather impossible for a user to contact the skin without even slightly vibrating the handle of the razor. The vibrating movements of the handle increase the risk of accidental cutting of the skin.